Stereo representations of the conformational changes between the different forms of C. violaceum Am:PyAT. (a) Superposition of the Cα traces of the apoenzyme (red), the holoenzyme (green) and the gabaculine complex (blue). The relatively stationary parts of the protein are shown in grey. (b) The conformational changes of the N-terminal region displayed as a cartoon with the same colour scheme as in (a). (c) The conformational changes of the loop regions 81–93 and 311–327 displayed as a cartoon with the same colour scheme as in (a).